[thin_repair, thin_dump] Don't look for better roots if the ones in the sb are ok.

Calculating the most recent trees is inexact, so trees other than the ones
in the superblock, which presumably are the most recent, could be chosen.
This commit is contained in:
Joe Thornber 2019-05-27 16:43:32 +01:00
parent 5e6ddbf2da
commit 0624ded67f

View File

@ -741,6 +741,63 @@ namespace {
// metadata snap, we really don't know
return 0ull;
}
void
metadata_repair_(block_manager<>::ptr bm, emitter::ptr e)
{
// We assume the superblock is wrong, and find the best roots
// for ourselves. We've had a few cases where people have
// activated a pool on multiple hosts at once, which results in
// the superblock being over written.
gatherer g(*bm);
auto tm = open_tm(bm, superblock_detail::SUPERBLOCK_LOCATION);
auto p = g.find_best_roots(*tm);
metadata::ptr md;
if (p) {
// We found good roots, so we fill out our own superblock,
// with some help from the old sb.
// FIXME: what happens if the superblock can't be read?
// catch and fill out defaults? what should the data_block_size be?
auto sb = read_superblock(*bm);
sb.metadata_snap_ = 0;
sb.device_details_root_ = p->first;
sb.data_mapping_root_ = p->second;
sb.metadata_nr_blocks_ = bm->get_nr_blocks();
md.reset(new metadata(bm, sb));
} else {
// We couldn't find any good roots, so we'll fall back to using the
// on disk superblock.
md.reset(new metadata(bm, false));
}
dump_options opts;
details_extractor de(opts);
device_tree_detail::damage_visitor::ptr dd_policy(details_damage_policy(true));
walk_device_tree(*md->details_, de, *dd_policy);
e->begin_superblock("", md->sb_.time_,
md->sb_.trans_id_,
md->sb_.flags_,
md->sb_.version_,
md->sb_.data_block_size_,
get_nr_blocks(md),
boost::optional<block_address>());
{
mapping_tree_detail::damage_visitor::ptr md_policy(mapping_damage_policy(true));
mapping_tree_emitter mte(opts, md, e, de.get_details(), mapping_damage_policy(true));
walk_mapping_tree(*md->mappings_top_level_, mte, *md_policy);
}
e->end_superblock();
}
}
//----------------------------------------------------------------
@ -772,58 +829,17 @@ thin_provisioning::metadata_dump(metadata::ptr md, emitter::ptr e, dump_options
void
thin_provisioning::metadata_repair(block_manager<>::ptr bm, emitter::ptr e)
{
// We assume the superblock is wrong, and find the best roots
// for ourselves. We've had a few cases where people have
// activated a pool on multiple hosts at once, which results in
// the superblock being over written.
gatherer g(*bm);
auto sb = read_superblock(*bm);
auto tm = open_tm(bm, superblock_detail::SUPERBLOCK_LOCATION);
auto p = g.find_best_roots(*tm);
metadata::ptr md;
if (p) {
// We found good roots, so we fill out our own superblock,
// with some help from the old sb.
// FIXME: what happens if the superblock can't be read?
// catch and fill out defaults? what should the data_block_size be?
auto sb = read_superblock(*bm);
sb.metadata_snap_ = 0;
sb.device_details_root_ = p->first;
sb.data_mapping_root_ = p->second;
sb.metadata_nr_blocks_ = bm->get_nr_blocks();
md.reset(new metadata(bm, sb));
} else {
// We couldn't find any good roots, so we'll fall back to using the
// on disk superblock.
md.reset(new metadata(bm, false));
}
dump_options opts;
details_extractor de(opts);
device_tree_detail::damage_visitor::ptr dd_policy(details_damage_policy(true));
walk_device_tree(*md->details_, de, *dd_policy);
e->begin_superblock("", md->sb_.time_,
md->sb_.trans_id_,
md->sb_.flags_,
md->sb_.version_,
md->sb_.data_block_size_,
get_nr_blocks(md),
boost::optional<block_address>());
{
mapping_tree_detail::damage_visitor::ptr md_policy(mapping_damage_policy(true));
mapping_tree_emitter mte(opts, md, e, de.get_details(), mapping_damage_policy(true));
walk_mapping_tree(*md->mappings_top_level_, mte, *md_policy);
}
e->end_superblock();
if (get_dev_ids(*tm, sb.device_details_root_) && get_map_ids(*tm, sb.data_mapping_root_)) {
// The roots in the superblock look ok (perhaps the corruption was in the
// space maps). Just dump the metadata skipping repair.
dump_options opts;
auto md = metadata::ptr(new metadata(bm, false));
metadata_dump(md, e, opts);
} else
metadata_repair_(bm, e);
}
//----------------------------------------------------------------